TPS92638-Q1: Turn indicator is off when the input volage is at 16V to PCBA

Kannan E

Part Number: TPS92638-Q1

Tool/software:

Dear Sir,

We are using the TPS92638QPWPRQ1 IC in two of the locations (U1 & U2) of our LED PCBA .There are two test points connected with pin 8 (fault pin) of this IC.There are two test point connected with Pin 8 of U1 7 U2,Whenever we touch this TP15 or TP25,the turn indicator is not glowing and when we restart the power supply the turn indicator is working fine.There is one capacitor location in LAM PCBA (c26) when we short this capacitor c26,all the turn indicator function at 13.5V or 16V is working fine.I can share the schematic for both LAM and LDM PCBA .Please check the schematic and please let us know design flop if any,

6 months ago

0 Hailee Xu 6 months ago

TI__Expert 8660 points

Hi Kannan,

Could you share the full schematic? and do you have any test waveforms to describe your problems, like FAULT pin, Vin...? Thanks!

BR,

Hailee.

0 Kannan E 6 months ago in reply to Hailee Xu

Prodigy 10 points

https://we.tl/t-qFDpIQ95gj

Please find the link for schematic.Thank you for the reply.I will share the video to understand the problem.

0 Kannan E 6 months ago in reply to Kannan E

Prodigy 10 points

Hi Hailee Xu,

Please find the below link .There are two videos .When we touch the TP15 or TP25 the LED is off.Also I have attached the voltage measurement report for LED pcb.

https://we.tl/t-qF2ggAwdiZ

0 Kannan E 6 months ago in reply to Kannan E

Prodigy 10 points

One clue- If we short capacitor C26 and touching TP15 or TP25 the LED is working fine.Need to understand why when we short the C26 LED is working good and why when without shorting C26 LED is off whenw e touch TP15 Or TP25